Clinical Trial Comparing 3-D RT vs. IMRT in Post- Prostatectomy Prostate Cancer Patients

In 2015, the American Cancer Society estimates that almost 220,800 men are expected to be diagnosed with prostate cancer, and about 27,540 men are expected to die of this disease. Curative treatment of prostate cancer consists of either surgery (i.e., radical prostatectomy) or radiation therapy (RT). Approximately one-third of men who undergo a prostatectomy will require post-operative adjuvant or salvage RT. During the last 2 decades, the techniques used to deliver RT have evolved from 2-D RT in the 1980's and early 1990's, to 3-D conformal RT (3-D CRT) in the late 1990's, to intensity modulated radiation therapy (IMRT) within the last decade. To date, no randomized prospective head to head comparison between 3-D CRT and IMRT to assess toxicity differences has ever been conducted in the treatment of post-prostatectomy prostate cancer patients. Retrospective evidence suggests comparable acute and late genitourinary (GU) and gastrointestinal (GI) toxicity. In addition, no postoperative randomized trials investigating hormonal therapy (HT) and RT have been published, but three prior phase III studies of men treated definitively for prostate cancer, one by the Radiation Therapy Oncology Group (RTOG) (86-10), one by investigators at Harvard, and one by the Trans-Tasman Radiation Oncology Group, concluded that neoadjuvant and concurrent short-term hormonal therapy (i.e., 4-6 months) RT reduces cause-specific mortality compared with RT alone. The purpose of this study is to estimate, correlate, and compare the incidence of acute rectal, bladder and other acute toxicities between 3-D CRT and IMRT in prostate cancer patients treated with post-operative radiation therapy, to quantify, compare, and correlate the dose volume histogram (DVH) doses (e.g., Vmean, Vmedian, V25, V50, V75) to the surrounding critical organs (i.e., rectum and bladder) between 3-D CRT and IMRT, and to measure, compare, and correlate the quality of life scores of participants using the EORTC Quality of Live Questionnaires (QLQ), called "QLQ-C30" and "EPIC-26". These survey instruments will measure quality of life differences during the study; the comparison will be done between 3-D CRT and IMRT treatment arms. Hormonal therapy will also be required for patients with high risk disease (both the adjuvant and salvage groups) and as per standard of care for patients with low risk disease, but is not explored in this study. There are 2 arms (groups) in this study: Arm 1: 3-D Conformal Radiation Therapy (plus hormonal therapy) Arm 2: Intensity Modulated Radiation Therapy (plus hormonal therapy)